Watch attachment



' in the usual manner.

Patented Feb. 4, 1936 UNITED STATES PATENT OFFICE 3 Claims.

The invention relates to watches and has for its object to provide in connection with a watch winding mechanism detent means cooperating with the finger engaging winding end of the stem for holding said stem and gear train connection to the watch spring against retrograde rotation in case of breakage of the latch cooperating with one of the gears of the gear train, thereby preventing breakage of the spring when the latch is broken.

A further object is to provide means carried by the stem bow, which when the bow is pivotally moved into the plane of the stem will cooperate with the stem end and hold the same against rotation.

A further object is to provide means cooperating with a watch winding stem for preventing rotation of said stem upon breakage of the winding latch within the watch.

A further object is to provide the inner side of the pivoted bow with an arm which moves into a transverse slot in the finger engaging portion of the stem for holding the stem against rotation.

With the above and other objects in View the invention resides in the combination and arrangement oi parts as hereinafter set forth, shown in the drawing, described and claimed, it being understood that changes in the precise embodiment of the invention may be made within the scope of what is claimed without departing from the spirit of the invention.

In the drawing:

Figure'l is a perspective view of the stem portion of a conventional form of watch, showing the device applied thereto.

Figure 2 is a vertical transverse sectional view through the stem end of a conventional form of watch showing the device applied thereto.

Figure 3 is a vertical longitudinal sectional view through the stem end of the watch.

Referring to the drawing, the numeral I designates the case ring of a conventional form of watch and within which the works are placed The watch works is provided with the usual plate 2 on which the parts are assembled. In the present device there is no modification of the watch works. or stem structure except the detent means used in connection therewith. The stem 3 extends radially into the watch case through the extension 4 in the usual manner, and which extension is provided with a chain receiving pivoted bow 5 of conventional structure. The pivoted bow 5 is pivoted in a manner whereby it may swing to one side of the stem or to a position in the plane of the stem as plainly shown in full and dotted lines in Figure 2. The stem is provided with a pinion 6 on its inner end, which pinion meshes with a gear 'I preferably of the pin type on the inner face of the gear 8.

The gear 8 meshes with the spring winding gear 9, which rotates in the direction of the arrow a (Figure 3) during a winding operation, and at which time the gear 8 rotates in the direction of the arrow b. This winding operation tensions the spring IU in the usual manner for operating the watch mechanism. Gear 9 is held against retrograde movement by the usual latch II having a tooth I2, which cooperates with the teeth of the gear 9. It has been found that the latch I I often breaks or does not operate properly, and this action allows a rapid unwinding of the spring I0, consequently the spring breaks and this would not be possible if means were provided for preventing the reverse rotation of the gears forming the gear train between the stem 3 and the spring.

To prevent retrograde rotation of the gear train and winding stem 3, the knurled finger engaging portion I3 thereof is provided with a transversely disposed slot I4 which receives the inwardly extending finger I5 .extending inwardly from the pivoted bow 5 as clearly shown in Figure 2. It will be noted that the slot I4 is concentric with the pivot point I6 of the chain bow 5, hence the finger I5 will move out of the slot when the bow 5 is moved to the dotted line position shown in Figure 2 to one side of the watch. When the bow 5 is in the position shown in dotted lines in Figure 2, the operator can easily grasp the knurled finger engaging portion I3 and rotate the same for the winding operation. After the winding operation the bow 5 is moved to its normal position in the plane of the watch and the finger I5 will be received in the slot I4; therefore it will be seen that as the finger is off round or 40 transversely fiat, it will cooperate with the walls of the slot- I4 and will prevent rotation of the stem 3 in case of retrograde rotation of the gear train.

From the above it will be seen that means is provided in connection with a watch winding stem for holding the same against retrograde rotation and the gear train also against retrograde rotation in case of breakage of detent means within the watch, thereby preventing rapid eX- pansive strain on the spring in its unwinding operation and breakage thereof.

A conventional form of watch mechanism is shown. However it is to be understood that this may be varied and the device applied to watches of any construction. Y

The invention having been set forth what is claimed as new and useful is:

1. The combination with a watch stem extending outwardly from a watch and adapted to tension a watch spring within the watch, and a pivoted chain bow, of means carried by the chain bow and cooperating with the stem for preventing retrograde rotation of the stem.

2. A device as set forth in claim 1 wherein the chain bow is providedwith an arm, a groove in the stem, said arm being positioned to be received Within the groove in the stem when in a predetermined position.

3. The combination with a watch stem rotatably mounted in an extension carried by the watch casing, a transverse slot in said stem, and a chain bow pivotally connected to said extension and adapted to arch the end of the stem, of an inwardly extending nger carried by said bowV and receivable in the transverse slot in the stem end and forming means whereby said stem is held 10 against retrograde rotation when the bow is moved to position the finger within the slot.

Y AUGUST H. FISCHER. 

